Apparatus for conveying and depositing overlapped sheets of paper and the like

ABSTRACT

Apparatus for conveying sheets emanating from transverse cutters or other sheet-ejecting machines in a flow line of successive end to end sheets in which the sheets are overlapped by upper and lower conveyor belt means with conveyor belt drive means being operative to move one conveyor belt means slower than the other conveyor belt means so that each successive sheet is overlapped with the immediately preceding sheet, the slower moving conveyor belt being stopped in response to the absence of at least one sheet in the flow line of successive sheets, the drive means for the slower conveyor belt means including a differential gear means including an input drive shaft and two driven shafts and means are operatively associated with said differential gear means for alternatively stopping and releasing both driven shafts.

O U nlted States Patent 3,565,423

[72] inventor Engelbert Kluth [56] References Cited Dusseldorf, GermanyUNITED STATES PATENTS 1 Appl- 782,256 2 852 256 9/1958 Faulls Jr. et al271 76 [22] Filed Dec. 9,1968 l 45 patented M 23, 1971 PnmaryExammerEvon C. Blunk [73] Assignee Jagenberg-Werke AG AssistantExaminer-Joseph Wegbreit Dusseldorf, Germany Attorney-Burgess, Dinklage& Sprung [32] Priority Dec. 8,1967

3 2 33 ABSTRACT: Apparatus for conveying sheets emanating fromtransverse cutters or other sheet-e ecting machmes in a flow line ofsuccessive end to end sheets in which the sheets are overlapped by upperand lower conveyor belt means with conveyor belt drive means beingoperative to move one conveyor l t t b t ATUS FOR CONVEYmG ANDDEPOSITING be t means slower han he other conveyor el means so that KEeach successive sheet 15 overlapped with the lmmedlately OVERLAPPED S EOF PAPER AND THE L] preceding sheet, the slower moving conveyor beltbeing 4 Claims 4 Drawmg stopped in response to the absence of at leastone sheet in the [52] US. Cl 271/76, flow line of successive sheets, thedrive means for the slower 271/64 conveyor belt means including adifferential gear means in- [51] Int. Cl. B65h 29/18 eluding an inputdrive shaft and two driven shafts and means [50] Field of Search 271/77, 76, are operatively associated with said differential gear meansfor alternatively stopping and releasing both driven shafts.

APPARATUS FOR CONVEYING AND DEPOSITIN G OVERLAPPED SHEETS OF PAPER ANDTHE LIKE The removal of a defective sheet takes place prior to the timewhere the sheets become overlapped through reduction in their advancespeed, so that there necessarily occurs a gap in the continuous flow ofthe overlapped sheets. Such. a gap represents an interruption in thesheet-overlapping process, bringing about the danger that the frontaledge of the sheet following the removed or diverted sheet strikes orshoves upon the rear edge of the sheet preceding the removed sheet, thusresulting in disturbances during further conveying and depositing ,ofthe sheets.

In order to prevent this type of disturbances, it has been proposed thatthe slower-running conveyor belts be stopped j for a short intervalduring removal of a defective sheet so as to avoid the development. ofa-gap in the-overlapped sheet succession. In this known embodiment, theconveyor belts were stopped by means of a'brake acting upon theslower-running conveyor belts and a coupling devi'cewhich was connectedwith the drive for the conveyor .belts..lt became apparent,

correspondingly quick or rapid movement of a succession of sheets, sothat a timely stopping and restarting of the conveyor belts independencyupon the activity of the divertor or gate was not ensured.

The object of the present invention is to provide for a .control meansfor the slower running conveyor belts whose time for responding will beso short as to prevent the aforementioned drawbacks from appearing, andwherein said: control means meets the expected requirem'entsregardingfunctional safety by virtue of its simple construction at lowexpenditure.

Proceeding from an apparatus for conveying sheets emanating fromtransverse cutters or other sheet-ejecting machines which are beingtransferred by their becoming overlapped during such a phase, fromfaster running conveyor belts to slower-running conveyor belts which arestopped when one or several sheets are missing from the continuous flowof sheets in advance of the slower-running conveyor belts, it is nowproposed to solve this object by connecting a differential gear with thedrive for the slower running conveyor belts. This differential gear hasassociated with it a device for alternatingly stopping and releasing twodriven shafts, In this arrangement, one of the two driven shafts of thedifferential gear drivesthe slower running conveyor belts while the.other driven shaft is constructed as an idler shaft which can bestopped. The power train through the differential gear is transmittedwhile the idler shaft is stopped or held by the continuously runningdrive shaft via the released driven shaft forthe conveyor belts, whereasthe power train with the conveyor belt driven shaft being stopped orheld, is transmitted by the drive shaft to the released idler shaft. Thearrangement is furthermore constructed such that both of thedrivenshafts of the differential gear are each provided with a band brake soarranged that-the pulling end portions of the brake bands can beactuated by a common cylinder piston unit.

Further and more specific objects of the invention wilibe apparent fromthe following description taken in connection with the accompanyingdrawings in which:

FIG. 1 is a diagrammatic side view illustrating a transverse v cutterand sheet moving system embodying the present invention;

FIG. 2 is a diagrammatic side view illustrating preferred embodiment ofthe conveyor belt drive,

FIG. 2a is a top plan view of the arrangement shown in. FIG. 2, and

FIG. 3 is a diagrammatic view illustrating a further embodiment of theconveyor belt drive.

As can be seen particularly well in FIG. 1, the paper web 2 emanatingfrom feed or supply roll 1. is fed through a flaw detection device 3 andthen led through advancing or feed rollers 4 to a transverse cutterdevice comprising a pair of rotary knives 5 which divides the paper web2 into individual sheets 6. The sheets 6 then reach the area of gate ordiverter 8 via a feeder table 7. This gate or diverter 8 is intheposition as shown in the drawing sothat the moving sheets 6 passbetween the fast running conveyor belts or tapes 9, 10, 11. Aphotoelectric cell 12 scanningthe succession of sheets is mounted in thearea of these conveyor belts. As sheets 6 move along, they reach theoverlapping station which is formed by the lower and slower movingconveyor belts or tapes 13 cooperating with the upper conveyor belts ortapes 11. Thereafter, the sheets 6 are deposited on stack-or layboy 14.

The drive for the slower moving conveyor belts 13 is effected through adifferential gear means 15. As described above, this differential gearmeans 15 is constructed and mounted in such'manner that, as a defectivesheet is being removed resulting necessarily-in the development of a gapin the flow line of sheets, an impulse is initiated bythe photoelectriccell 12 to the drive for the slower moving conveyor belts vl3 so thatthese conveyorbelts' 13 can'be stopped for a brief interval.

As mentioned supra,,the1activation-of gate.8 during the appearance of'adefectivegspot takes place by means of an impulse emanating fromthe flaw'detectiondevice 3, said impulse being transmitted to a magnet l7 actingupon lever. 16 of gate 8. The oscillating mqvementof gate 8 therebycauses the deflection of defective sheet onto defective stack 22'viaconapparatus. Of the two driven shafts of the differential gear means,shaft 24 is constructed as an idler shaft, whereas shaft 25, drivesroller26 around whichconveyor belts 13 are wound, FIG. 2a. .Brake discs27 and 28 are securedto the extensions of the driven shafts 24 and 25and have brake bands 29-and 30 associated therewith.

One end of each of these brake bands 29 and 30 are each connected with astationary point 21, whereas the other or pulling end portions of eachbrake band are connectedto the opposite ends of the piston of adouble-acting cylinder piston unit 32 which is fed from a compressed airsource, not shown, under control 0521 magnetically actuate valve 33.Thevalve 33 is activated by means of an impulse initiated byphotoelectric cell 12 scanning the succession of sheets.

In the operative embodiment as shown in the drawing, in

which an uninterrupted sequence of sheets is conveyed to flawless stack14, theslow-moving conveyor belts l3-run continuously. In this mode ofoperation the power train through gear means 15 is transmitted toconveyor belts 13 by drive shaft 23, while the driven idler shaft 24 isbeing braked or held and driven shaft 25 released. If as a result ofdetecting a defective sheet and the actuation of gate 8 releasedthereby, a gap develops in the succession of sheets being conveyed toflawless stack 14, photoelectric cell 12 senses this gap and sends animpulse to magnetic valve 33 with the effect that driven shaftZS isstopped'throughthe movement of the'piston in cylinder 32 to the left,and driven shaft 24 is released. During this phase, the conveyor belts'13 are stopped, and the power train through the gear 15 istransmittedby the drive shaft 23 to the .driven idlershaft 24 which hasbeen-released and is working as an idling shaft. As soon as the gaphaspassed the magnetically actuated valve is released and the piston inpiston-cylinder unit 32 is'moved to the right to release shaft 25 andhold shaft 24 whereupon conveyor belts 13 are again driven.

FIG. 3 shows a modification of the conveyorlbelt drive in such fashionthat thedriven shafts 24 and 25 which are provided with brake discs 27and 28 are positioned opposite of each other. In this embodiment, brakediscs 27 and '28 have associated with them brake shoes 34 and 35 whichin conformity with the brake bands 29 and 30 of the abovedescribedembodiment alternatingly stop and release the driven shafts 24 and 25 ofdifferential gear 15. Otherwise, the method of operation and effectscorrespond to the drive of the conveyor belts as depicted in FIG. 2.

it is therefore clear that this invention provides a system forconveying and depositing sheets that emanate from a cross cutter whichincludes:

1. means for moving a paper web to a cross cutter so that the web is cutinto individual sheets;

2. means in advance of the cross cutter for sensing or detecting a flawin the web;

3. means for receiving and moving ejected cut sheets from the crosscutter in a flow line of successive sheets in endto-end relation;

4. movable means interposed in said last-mentioned means and operativein response to said sensing means for diverting a sheet having a flawtherein from said flow line;

5. means for moving diverted sheets to a stack;

6. means for overlapping successive sheets including upper and lowerconveyor belt means and means for driving the lower conveyor belt meansat a slower speed to permit a successive sheet to overlap a preceedingsheet, and for delivering the sheets to another stack;

7. a differential drive gear including a continuously rotating inputdrive shaft and two driven shafts, one of said driven shafts drivingsaid slower conveyor belt means and the other driven shaft constitutingan idler shaft;

8. means for alternatively holding said idler shaft stationary andreleasing said one driven shaft to allow the input shaft to drive saidslower moving conveyor and for releasing said idler shaft and holdingsaid one driven shaft to stop said slower moving conveyor belt meanswithout stopping said input shaft;

9. sensing means operatively associated with the means for moving thesheets in a flow line of successive sheets in advance of said slowermoving conveyor belt means for detecting a gap in said flow lineoccasioned by the absence of at least one diverted sheet for indicatinga command impulse responsive to such a gap,

10. and means operative in response to such initiated command impulsefor controlling the means for alternatively releasing and holding saiddriven shafts to actuate the same to release said idler shaft and holdsaid one shaft to stop said slower moving conveyor belt means while saidgap exists and to hold said idler shaft and release said one drivenshaft to allow said slower conveyor belt means to move when said gap isclosed by another moving sheet.

Design and mode of operation of the flaw detector 3 and of magnet 17 foractuating the gate 8 are described and shown in the U.S. Pat. No.3,070,365. The photoelectric cell 12 and the magnetic valve 33 foractuating the cylinder piston unit 32 are commercially availableelectro-optical or hydraulic units respectively. The differential gear15 also represents, as can be recognized in FIG. 2a and 3, a knowndesign which, in its basic form and in its mode of operation is forexample used in motor vehicle construction.

lclaim:

1. ln apparatus for conveying sheets emanating from a transverse cutteror other sheet ejecting machines, means for receiving and moving ejectedsheets in a flow line of successive end-to-end sheets, means foroverlapping moving sheets including upper and lower conveyor belt means,drive means for said conveyor belt means including means operative tomove one conveyor belt means slower than the other conveyor belt meansso that each successive sheet is overlapped with the immediatelypreceding sheet, means for stopping said slower moving conveyor beltmeans in response to the absence of at least one sheet in the flow-lineof successive sheets, and the drive means for said slower conveyor beltmeans including a differential gear means including an input drive shaftand two driven shafts and means operatively associated with saiddifferential gear means for alternatively stopping and releasing bothdriven shafts.

2. Apparatus as claimed in claim 1 in which one of said two drivenshafts of the differential gear means drives the slower moving conveyorbelt means, while the other driver shaft is an idler shaft which can bestopped.

3. Apparatus as claimed in claim 2 in which said input shaft of thedifferential gear means is continuously rotating, the power trainthrough said differential gear means being transmitted to the slowerconveyor belt means from said input shaft by said one driven shaft whensaid idler shaft is stopped and said one driven shaft released, and thepower train through said differential gear means being transmitted fromsaid input shaft to said idler shaft when said one driven shaft isstopped to stop said slower moving conveyor belt and said idler shaft isreleased.

4. Apparatus as claimed in claim 3 in which the means operativelyassociated with said differential gear means for alternatively stoppingand releasing both driven shafts includes a band brake means for eachdriven shaft, each bank hand brake means having a pulling end, acylinder, a piston means movable within said cylinder and havingopposite end portions, said pulling ends of the band brake means beingconnected to the opposite end portions of said piston means, and meansfor controlling reciprocating movement of said piston means so that whenone band means is applied to stop its associated driven shaft, the otherband means releases its associated driven shaft when the piston meansmoves in one direction, and said other band means is applied to andstops its associated driven shaft and said one band means releases itsassociated driven shaft when the piston means moves in the oppositedirection.

Patent No. 3,565 ,423 Dated February 23 1971 Inventor(s) Engelbert KluthIt is certified that error appears in the above-identified patem andthat said Letters Patent. are hereby corrected as shown below:

Column 1 after line 3 inster the following:

The present invention relates to apparatus for cor veying and depositingoverlapped sheets of paper or the lik after they have been ejected fromtransverse cutters or 0th 3 sheet-producing or sheet-processing machinesIt is customary in machines of this type, especial with high-speedtransverse cutters, to delay the sheets lea the transverse cutter deviceto such an extent that the she become overlapped during this delay so asto ensure disturb v free deposit 1 on the stack or layboy. The reductionin the of advance of the sheets takes place in such manner that seconveyor belts transporting the sheets are connected serial successivelylower speeds. As a result of this arrangement sheet advancing at ahigher speed moves with its frontal ed onto the rear end of thepreceding sheet, whose underside i already located in the operative zoneof a conveyor belt wh llies at a lower level and also runs at a reducedspeed.

FORM PO-1n50 [10-69) span-LP.- nn' UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION Patent No. ted 23,

Inventor(s) Engelbert Kluth PAGE 2 It is certified that error appears inthe above-identified patent and that said Letters Patent are herebycorrected as shown below:

Moreover, it is known in paper-working machinery, t1

verse cutters and the like that sheets having glue spots or defectiveportions must be removed since they would cause di:

turbances, for example in printing presses, if they were proc essedfurther. To provide for removal of such defective sh one uses physical,optical or electronic flaw detection devi which initiate an impulse uponthe appearance of a flaw in t] paper web or in the sheet. This impulsein turn activates a device, for example a gate or deflector movable intothe lin of advance of the sheets to divert or cause removal of the s.possessing the flow. The diverted or removed sheet or sheet being thendeposited on a separate stack.

Signed and sealed this 2nd day of November 1971 (SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer ActingCommissioner of Pa

1. In apparatus for conveying sheets emanating from a transverse cutteror other sheet ejecting machines, means for receiving and moving ejectedsheets in a flow line of successive end-to-end sheets, means foroverlapping moving sheets including upper and lower conveyor belt means,drive means for said conveyor belt means including means operative tomove one conveyor belt means slower than the other conveyor belt meansso that each successive sheet is overlapped with the immediatelypreceding sheet, means for stopping said slower moving conveyor beltmeans in response to the absence of at least one sheet in the flow-lineof successive sheets, and the drive means for said slower conveyor beltmeans including a differential gear means including an input drive shaftand two driven shafts and means operatively associated with saiddifferential gear means for alternatively stopping and releasing bothdriven shafts.
 2. Apparatus as claimed in claim 1 in which one of saidtwo driven shafts of the differential gear means drives the slowermoving conveyor belt means, while the other driver shaft is an idlershaft which can be stopped.
 3. Apparatus as claimed in claim 2 in whichsaid input shaft of the differential gear means is continuouslyrotating, the power train through said differential gear means beingtransmitted to the slower conveyor belt means from said input shaft bysaid one driven shaft when said idler shaft is stopped and said onedriven shaft released, and the power train through said differentialgear means being transmitted from said input shaft to said idler shaftwhen said one driven shaft is stopped to stop said slower movingconveyor belt and said idler shaft is released.
 4. Apparatus as claimedin claim 3 in which the means operatively associated with saiddifferential gear means for alternatively stopping and releasing bothdriven shafts includes a band brake means for each driven shaft, eachbank band brake means having a pulling end, a cylinder, a piston meansmovable within said cylinder and having opposite end portions, saidpulling ends of the band brake means being connected to the opposite endportions of said piston means, and means for controlling reciprocatingmovement of said piston means so that when one band means is applied tostop its associated driven shaft, the other band means releases itsassociated driven shaft when the piston means moves in one direction,and said other band means is applied to and stops its associated drivenshaft and said one band means releases its associated driven shaft whenthe piston means moves in the opposite direction.